Tematica I structure of solids, structural phase transitions, defects -resp. S. Nistor, F. Vasiliu

Referinte (selectie)

[A1] Grimberg R, Savin A, Steigmann R, et al., “Electromagnetic non-destructive evaluation using metamaterials”, INSIGHT, 53 132-137 (2011).

[A2] Popescu VA , “Efficiency of Traveling-Wave Photodetectors in Superconducting Box-Shaped Metamaterial Optical Waveguides”, JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM, 23, 1421-1425 (2010).
[A3] Ionita I, Dragoman D, “Anisotropic composite right/left-handed-material switch” JOURNAL OF APPLIED PHYSICS, 106, 053111 (2009).
[A4] Zamfirescu M, Dabu R, Dumitru M, et al. Femtosecond Laser Fabrication of Metamaterials for High Frequency Microwave Devices, JOURNAL OF LASER MICRO NANOENGINEERING, 3, 5-8 (2008).
[A5] Dabu R, Zamfirescu M, Dumitru M, et al., Femtosecond lasers - potential tools for manufacturing high-frequency negative refractive materials - art. no. 70220L, Conference on Advanced Laser Technologies, SEP 03-07, 2007 Levi, FINLAND - ADVANCED LASER TECHNOLOGIES 2007 Book Series: PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) Volume: 7022 L220-L220 (2008)

B. Medii active laser – importante in perspectiva dezvoltarii experimentului ELI-NP. De dezvoltat de cineva din INCDFLPR???

IV.2 Tehnici spectroscopice de investigare a materiei condensate
Realizari recente si perspective

- spectroscopie IR, FTIR, Raman: studiul fononilor in nanostructuri (nanotuburi, fire si doturi cuantice), interactia fononilor cu alte quasiparticule, fononi in structuri hibride, ingineria modurilor fononice pentru aplicatii termoelectrice [I. Baltog, M. Baibarac, S. Lefrant, Phys. Rev. B 72, 245402 (2005);W.L. Liu and A.A. Balandin, J. Appl. Phys. (2005); N D Zincenco, D L Nika, E P Pokatilov and A A Balandin, J. Phys.: Conf. Series, 92, 012086 (2007)]

- spectroscopie de absorbtie si reflexie UV-VIS: semiconductori de banda larga, semiconductori organici monomerici sau polimerici

- fotoluminescenta, catodoluminescenta: studiul defectelor si distributiei lor spatiale in nanostructuri, excitoni in cristale si nanostructuri, studiul cuplajului exciton-fonon

- elipsometrie: studiul filmelor subtiri din semiconductori organici si anorganici, si al filmelor polimerice pentru o clasa larga de aplicatii
Contributie romaneasca recenta si obiective propuse

Exista grupuri puternice cu rezultate remarcabile in ceea ce priveste temele de cercetare enuntate, la toate centrele cu activitate de cercetare in fizica din tara, atat in institutele de cercetare cat si in universitati (Bucuresti, Cluj Napoca, Iasi). Preocuparile cercetatorilor romani in domeniu vizeaza atat fizica aplicata cat si pe cea fundamentala. Sunt de asemenea vizate subiecte de cercetare interdisciplinare, la interfata cu biologia si medicina (numarul articolelor publicate, avand acest caracter, cu autori romani este intr-o crestere semnificativa in ultimii cinci ani). Dintre subiectele identificate, acesta este cel la a carui dezvoltare cercetatorii romani au contributia cea mai consistenta.

Referinte (selectie)

[1] Stefan M, Nistor SV, Ghica D, et al., Substitutional and surface Mn2+ centers in cubic ZnS:Mn nanocrystals. A correlated EPR and photoluminescence study, PHYSICAL REVIEW B 83 045301 (2011)

[2] Secu M, Secu CE, Ghica C, Eu3+-doped CaF2 nanocrystals in sol-gel derived glass-ceramics, OPTICAL MATERIALS 33 613-617 2011

[3] Ciurea ML, Lazanu S, Stavarache I, et al., Stress-induced traps in multilayered structures, JOURNAL OF APPLIED PHYSICS 109 013717 2011

[4] Baibarac M, Baltog I, Lefrant S, et al. Polydiphenylamine/carbon nanotube composites for applications in rechargeable lithium batteries, MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS 176 110-120 2011

[5] Cernea M, Secu M, Secu CE, et al., Structural and thermoluminescence properties of undoped and Fe-doped-TiO2 nanopowders processed by sol-gel method JOURNAL OF NANOPARTICLE RESEARCH 13 77-85 2011

[6] Lefrant S, Baibarac M, Baltog I, Raman and FTIR spectroscopy as valuable tools for the characterization of polymer and carbon nanotube based composites JOURNAL OF MATERIALS CHEMISTRY 19 5690-5704 2009

[7] Baibarac M, Baltog I, Lefrant S Photoluminescence and Raman spectroscopy studies on polyaniline/PbI2 composite, JOURNAL OF SOLID STATE CHEMISTRY 182 827-835 2009

[8] Enculescu M, Morphological and optical properties of doped potassium hydrogen phthalate crystals PHYSICA B-CONDENSED MATTER 405 3722-3727 2010

[9] Ristoscu C, Ducu C, Socol G, et al. Structural and optical characterization of AlN films grown by pulsed laser deposition APPLIED SURFACE SCIENCE 248 411-415 2005

[10] Potara M, Gabudean AM, Astilean S, Solution-phase, dual LSPR-SERS plasmonic sensors of high sensitivity and stability based on chitosan-coated anisotropic silver nanoparticles JOURNAL OF MATERIALS CHEMISTRY 21 3625-3633 2011

[11] Rada S, Chelcea R, Culea M, et al. The improvement of the amorphous environment of the germanate-tellurate glasses in the presence of the gadolinium ions JOURNAL OF MATERIALS SCIENCE 46 1289-1294 2011

IV.3 Fotoconductie si efect fotovoltaic

Realizari recente si perspective

Este un subiect de cercetare cu evolutie spectaculoasa in ultima decada, data fiind importanta lui pentru industria energetica. Ca principale realizari si, totodata, perspective de dezvoltare, pot fi enumerate:

- filme subtiri optimizate pentru aplicatii in optoelectronica si conversia fotovoltaica a energiei solare: conductori transparenti optic, structuri fotovoltaice multistrat cu raspuns spectral larg si eficienta mare de conversie, filme nanostructurate utilizate ca electrozi in structuri fotovoltaice

- materiale polimerice/materiale soft functionalizate cu aplicatii in conversia fotovoltaica

- materiale cu raspuns optoelectronic rapid; sisteme fotonice reconfigurabile
Contributie romaneasca recenta si obiective propuse

In ceea ce priveste producerea si caracterizarea de filme subtiri pentru aplicatii optoelectronice/fotovoltaice, exista grupuri puternice, cu o buna vizibilitatea internationala, la Institutul National de Cercetare&Dezvoltare pentru Fizica Laserilor, Plasmei si Radiatiilor Bucuresti, Universitatea din Bucuresti-Facultatea de Fizica, Institutul National de Cercetare&Dezvoltare pentru Fizica Materialelor Bucuresti, Universitatea Al. I. Cuza din Iasi; sunt utilizate metode de procesare cu laser, in plasma, etc. Ca un exemplu, au fost obtinute cu succes filme conductoare optic transparente de tip ZnO:Al si ZnO:In cu stabilitate chimica superioara celei a ITO.

In ceea ce priveste structurile fotovoltaice, grupurile principale sunt la Universitatea din Bucuresti-Facultatea de Fizica si Institutul National de Cercetare&Dezvoltare pentru Izotopi si Tehnologii Moleculare din Cluj Napoca (in ultimul caz abordarile sunt mai degraba conjuncturale, in principal datorita unor colaborari cu grupuri din SUA). Preocuparile vizeaza structurile multistrat si pe cele hibride semiconductor organic/semiconductor anorganic.

Sunt vizate atat fizica aplicata cat si cea fundamentala (optimizarea proceselor de absorbtie ale fotonilor, a proceselor de transfer de sarcina la electrod, etc.).

Data fiind importanta domeniului, este necesara o mai buna cooperare si utilizare a resurselor de care dispun cercetatorii romani care abordeaza acest subiect, precum si o deschidere mai larga spre sfera aplicatiilor practice.


Referinte (selectie)

[1] Ghica C, Ion L, Epurescu G, et al., Organic Photovoltaic Cells Based on ZnO Thin Film Electrodes, JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 10 1322 2010

[2] Sima C, Grigoriu C, Antohe S , Comparison of the dye-sensitized solar cells performances based on transparent conductive ITO and FTO THIN SOLID FILMS 519 595 2010

[3] Craciun D, Socol G, Stefan N, et al., Structural investigations of InZnO films grown by pulsed laser deposition technique THIN SOLID FILMS 518 4564 2010

[4] Craciun D, Socol G, Stefan N, et al., Structural investigations of ITO-ZnO films grown by the combinatorial pulsed laser deposition technique APPLIED SURFACE SCIENCE 255 5288-5291 2009

[5] Lee J-H., Atherton T., Petschek R.G., Barna V., De Luca A., Bruno E., Rosenblatt C., "Direct measurement of surface-induced orientational order parameter profile above the nematic - isotropic phase transition temperature" Physical Review Letters, 102, 167801, 1-4, (2009)

[6] Li ZR, Kunets VP, Saini V, …, Biris AR, Biris AS, Light-Harvesting Using High Density p-type Single Wall Carbon Nanotube/n-type Silicon Heterojunctions ACS NANO 3 1407-1414 2009

[7] Badescu V Unified upper bound for photothermal and photovoltaic conversion efficiency JOURNAL OF APPLIED PHYSICS 103 054903 2008

[8] Vlad VI, Petris A, Bosco A, et al.,3D-soliton waveguides in lithium niobate for femtosecond light pulses JOURNAL OF OPTICS A-PURE AND APPLIED OPTICS 8 S477-S482 2006

IV.4 Proprietati optice ale nanostructurilor
Realizari recente si perspective

- metode optice de investigare a nanostructurilor

- metode ab initio de investigare/modelare a proprietatilor optice ale nanostructurilor

- cristale fotonice, nanofotonica

- excitoni si polaritoni in nanostructuri 2D, 1D, 0D: investigatii teoretice si experimentale, efecte ale interactiei Coulomb si ale interactiei electron-fonon, etc.

Contributie romaneasca recenta si obiective propuse

Exista grupuri de cercetatori romani (institutele de pe Platforma Magurele, Universitatea din Bucuresti, Universitatea Politehnica din Bucuresti, Universitatea Babes Bolyai din Cluj Napoca, Universitatea “Alexandru Ioan Cuza” din Iasi) cu contributii semnificative la aceste subiecte de cercetare (a se vedea referintele indicate mai jos).

In unele cazuri abordarile acestor subiecte par a fi conjuncturale; data fiind dezvoltarea lor pe plan mondial si in conditiile existentei unei competente demonstrate prin publicatii si proiecte de cercetare castigate prin competitii nationale/internationale, este de dorit o abordare mai sistematica, o mai stransa colaborare intre grupuri si o deschidere mai larga spre aplicatii.


Referinte (selectie)

[1] Rebigan R, Dinescu A, Kusko C, et al., Suspended polymeric photonic crystals - simulation and fabrication ADVANCED TOPICS IN OPTOELECTRONICS, MICROELECTRONICS, AND NANOTECHNOLOGIES V, Proceedings of SPIE-The International Society for Optical Engineering 7821 2010

[2] Rasoga O, Dragoman D ,Engineered beam shaping effect in anisotropic photonic crystals APPLIED OPTICS 49 2161-2167 2010

[3] Matei E, Ion L, Antohe S, Enculescu I, Multisegment CdTe nanowire homojunction photodiode NANOTECHNOLOGY 21 105202 2010

[4] Lefrant S, Baltog I, Baibarac M Optical Advanced Spectroscopic Techniques for the Study of Nano-Structured Materials Such as Carbon Nanotubes JOURNAL OF NANOELECTRONICS AND OPTOELECTRONICS 4 203 2009

[5] Baibarac M, Baltog I, Velula T, et al. ZnO particles of wurtzite structure as a component in ZnO/carbon nanotube composite JOURNAL OF PHYSICS-CONDENSED MATTER 21 445801 2009

[6] Inerbaev TM, Masunov AE, Khondaker SI, …, Plamada AV, Dobrinescu A, Kawazoe Y, Quantum chemistry of quantum dots: Effects of ligands and oxidation JOURNAL OF CHEMICAL PHYSICS 131 044106 2009

[7] Lefrant S, Baibarac M, Baltog I, Raman and FTIR spectroscopy as valuable tools for the characterization of polymer and carbon nanotube based composites JOURNAL OF MATERIALS CHEMISTRY 19 5690-5704 2009

[8] Chioncel MF, Diaz-Guerra C, Piqueras J, Shape-controlled synthesis and cathodoluminescence properties of elongated alpha-Fe2O3 nanostructures JOURNAL OF APPLIED PHYSICS 104 124311 2008
[9] Farcau C, Astilean S Probing the unusual optical transmission of silver films deposited on two-dimensional regular arrays of polystyrene microspheres JOURNAL OF OPTICS A-PURE AND APPLIED OPTICS 9 S345-S349 2007

[10] Baldea I, Koppel H, Cederbaum LS Collective quantum tunneling of strongly correlated electrons in commensurate mesoscopic rings EUROPEAN PHYSICAL JOURNAL B 20 289-299 2001

[11] Niculescu EC, Eseanu N Interband absorption in square and semiparabolic near-surface quantum wells under intense laser field EUROPEAN PHYSICAL JOURNAL B 79 313-319 2011
[12]. Eseanu N Intense laser field effect on the interband absorption in differently shaped near-surface quantum wells PHYSICS LETTERS A 375 1036-1042 2011

[13] Stokker-Cheregi F, Vinattieri A, Feltin E, et al.Quantum confinement dependence of the energy splitting and recombination dynamics of A and B excitons in a GaN/AlGaN quantum well PHYSICAL REVIEW B 79 245316 2009

[14] Barna V., De Luca A., Atherton T., Carbone G., Sousa M., Rosenblatt C. Optical nanotomography of anisotropic fluids, Nature Physics, 4, 869-872, (2008)

[15] Gurioli M, Zamfirescu M, Stokker-Cheregi F, et al. Polariton emission in GaN microcavities SUPERLATTICES AND MICROSTRUCTURES 41 284-288 2007

[16] Baibarac M, Preda N, Mihut L, et al. On the optical properties of micro- and nanometric size PbI2 particles JOURNAL OF PHYSICS-CONDENSED MATTER 16 2345-2356 2004

[17] Penciu RS, Kriegs H, Petekidis G, et al. Phonons in colloidal systems JOURNAL OF CHEMICAL PHYSICS 118 5224-5240 2003

[18] Schmitt OM, Thoai DBT, Gartner LBP, et al. Bose-Einstein condensation quantum kinetics for a gas of interacting excitons PHYSICAL REVIEW LETTERS 86 3839-3842 2001


Tema 5
V. Dielectrics, piezoelectrics, and ferroelectrics and their properties- L. Mitoseriu

Tema (denumire)	Dielectrics, piezoelectrics, and ferroelectrics and their properties
Cod PACS	77
Realizari recente (2000-2011)	894 publicatii cu autori din Romania (“ferroelectric” OR “multiferroic” OR “dielectric”) H = 26 Numar citari = 4108 Peste 100 lucrari publicate in fiecare an in medie (in ultimii 5 ani)
Perspective (tematici)	Domain structure; hysteresis Relaxor ferroelectrics PZT ceramics and other titanates Switching phenomena Polymers; organic compounds Multiferroics; artificial multiferroics Metal-ferroelectric-semiconductor structures; multilayers and superlattices Ferro-composites; low-k and high-k materials for electronics Dielectric materials for microwave applications Piezoelectric and pyroelectric materials for energy harvesting Nano-ferroics
Contributie romaneasca (publicatii deosebite)	Author(s): Buscaglia, MT; Viviani, M; Buscaglia, V; Mitoseriu, L; Testino, A; Nanni, P; Zhao, Z; Nygren, M; Harnagea, C; Piazza, D; Galassi, C Title: High dielectric constant and frozen macroscopic polarization in dense nanocrystalline BaTiO3 ceramics Source: PHYSICAL REVIEW B, 73 (6): Art. No. 064114 FEB 2006 KeyWords Plus: BARIUM-TITANATE CERAMICS; ABNORMAL GRAIN-GROWTH; PBTIO3 ULTRAFINE PARTICLES; FERROELECTRIC THIN-FILMS; PHASE-TRANSITION; PHENOMENOLOGICAL THEORY; PIEZOELECTRIC CERAMICS; HIGH-PERMITTIVITY; DOMAIN-STRUCTURE; LEAD-TITANATE Times Cited: 51 ISSN: 1098-0121 Article Number: 064114 DOI: 10.1103/PhysRevB.73.064114 Author(s): Zhao, Z; Buscaglia, V; Viviani, M; Buscaglia, MT; Mitoseriu, L; Testino, A; Nygren, M; Johnsson, M; Nanni, P Title: Grain-size effects on the ferroelectric behavior of dense nanocrystalline BaTiO3 ceramics Source: PHYSICAL REVIEW B, 70 (2): Art. No. 024107 JUL 2004 KeyWords Plus: BARIUM-TITANATE CERAMICS; PBTIO3 ULTRAFINE PARTICLES; DIELECTRICPROPERTIES; PHASE-TRANSITION; LEAD-TITANATE; PRESSURE; FINE; PEROVSKITES; BOUNDARIES; CRYSTAL Times Cited: 163 ISSN: 1098-0121 Article Number: 024107 DOI: 10.1103/PhysRevB.70.024107 Author(s): Pintilie, L (Pintilie, L.) Title: Extrinsic contributions to the apparent thickness dependence of the dielectric constant in epitaxial Pb(Zr,Ti)O-3 thin films Source: PHYSICAL REVIEW B, 75 (22): Art. No. 224113 JUN 2007 KeyWords Plus: ZIRCONATE-TITANATE FILMS; DIRTY DISPLACIVE FERROELECTRICS; CHEMICALVAPOR-DEPOSITION; ELECTRICAL-PROPERTIES; LEAKAGE CURRENTS; SINGLE-CRYSTAL; PIEZOELECTRIC PROPERTIES; ORIENTATION DEPENDENCE; PHASE-TRANSITION; CAPACITORS Times Cited: 15 ISSN: 1098-0121 Article Number: 224113 DOI: 10.1103/PhysRevB.75.224113 Author(s): Pintilie, L (Pintilie, L.); Vrejoiu, I (Vrejoiu, I.); Hesse, D (Hesse, D.); LeRhun, G (LeRhun, G.); Alexe, M (Alexe, M.) Title: Ferroelectric polarization-leakage current relation in high quality epitaxial Pb(Zr, Ti)O-3 films Source: PHYSICAL REVIEW B, 75 (10): Art. No. 104103 MAR 2007 KeyWords Plus: CHEMICAL-VAPOR-DEPOSITION; PB(ZRXTI1-X)O-3 THIN-FILMS; SOL-GEL; ELECTRONIC CONDUCTION; ELECTRICAL-PROPERTIES; DIELECTRIC-CONSTANT; CURRENT MECHANISMS; CAPACITORS; THICKNESS; FATIGUE Times Cited: 32 ISSN: 1098-0121 Article Number: 104103 DOI: 10.1103/PhysRevB.75.104103 Author(s): Vrejoiu I, Le Rhun G, Pintilie L, et al. Title: Intrinsic ferroelectric properties of strained tetragonal PbZr0.2Ti0.8O3 obtained on layer-by-layer grown, defect-free single-crystalline films Source: ADVANCED MATERIALS   Volume: 18   Issue: 13   Pages: 1657-+  Published: JUL 4 2006 Times Cited: 74  KeyWords Plus: CHEMICAL-VAPOR-DEPOSITION; ZIRCONATE-TITANATE FILMS; THIN-FILMS; ELECTRICAL-PROPERTIES; POLARIZATION; HETEROSTRUCTURES; DISLOCATIONS; DEPENDENCE; THICKNESS; DOMAINS ISSN: 0935-9648 DOI: 10.1002/adma.200502711 Author(s): Boerasu I, Pintilie L, Pereira M, et al. Title: Competition between ferroelectric and semiconductor properties in Pb(Zr0.65Ti0.35)O-3 thin films deposited by sol-gel Source: JOURNAL OF APPLIED PHYSICS   Volume: 93   Issue: 8   Pages: 4776-4783 Published: APR 15 2003 Times Cited: 40  KeyWords Plus: PYROELECTRIC PROPERTIES; ELECTRONIC CONDUCTION; CHEMICAL-VAPOR; TITANATE FILMS; CAPACITORS; MODEL; PBZRXTI1-XO3; INTERFACE; THICKNESS; INJECTION ISSN: 0021-8979 DOI: 10.1063/1.1562009 Author(s): Pintilie L, Vrejoiu I, Rhun GL, et al. Title: Short-circuit photocurrent in epitaxial lead zirconate-titanate thin films Source: JOURNAL OF APPLIED PHYSICS   Volume: 101   Issue: 6 Article Number: 064109   Published: MAR 15 2007 Times Cited: 18  KeyWords Plus: FERROELECTRIC PROPERTIES; ELECTRICAL-PROPERTIES; OPTICAL-PROPERTIES; BARIUM-TITANATE; HIGH-SPEED; CERAMICS; CAPACITORS; MEMORY; DETECTORS; FATIGUE ISSN: 0021-8979 DOI: 10.1063/1.2560217
Obiective de cercetare propuse (tematici)	Exista contributie Romaneasca recenta in urmatoarele tematici legate de domeniul „Dielectrics, piezoelectrics, and ferroelectrics and their properties”: Efecte de dimensiune in ceramici, straturi subtiri si nano-obiecte din materiale cu proprietati dielectrice, feroelectrice si piezoelectrice. Exista mai multe lucrari cu autori din Romania care au pus in evidenta efectul dimensiunilor grauntilor cristalini asupra proprietatilor macroscopice ale corpurilor ceramice (constanta dielectrica, polarizare). Exista un interes din ce in ce mai mare in directia straturilor subtiri feroelectrice si multiferoice, cu contributii semnificative in lamurirea efectelor de dimensiune asupra constantei dielectrice si asupra pierderilor prin conductie. Rolul interfetelor in materiale dielectrice, feroelectrice si multiferoice. Accentul a fost pus in principal pe interfata metal-feroelectric, existand modele noi propuse de autori din Romania care arata efectul polarizarii asupra barierei de potential la electrod. Recent a fost publicata intr-un jurnal de prestigiu o lucrare cu autori din Romania care demonstreaza fezabilitatea diodelor Schottky feroelectrice (Ferroelectric Schottky diode behavior from a SrRuO3-Pb(Zr0.2Ti0.8)O-3-Ta structure; Pintilie L, Stancu V, Trupina L, et Pintilie I. PHYSICAL REVIEW B   Volume: 82 Issue: 8 Article Number: 085319   Published: AUG 18 2010). Fenomene de transport in materiale dielectrice, feroelectrice si multiferoice. Contributii deosebite in elucidarea mecanismelor de transport in straturi epitaxiale din materiale de tip titanat. Efect fotovoltaic in materiale feroelectrice si multiferoice. Aceste materiale pot constitui o alternativa pentru detectori solizi de UV, dar pot fi cu potential de utilizare in conversia energiei luminoase in energie electrice. Sinteza diferitelor tipuri de materiale, folosind diferite tehnici experimentale. Au fost dezvoltate diferite tehnici de sinteza chimica a nanoparticolelor, combinate cu tehnologia ceramica clasica pentru obtinerea probelor masive. Au fost dezvoltate de asmenea metode chimice pentru obtinerea de nanocompozite, cum ar fi cele de tip core-shell. In acelasi timp, au fost dezvoltate si la noi in tara tehnicile de depunerea a straturilor subtiri bazate pe ablatie laser si pulverizare in radio-frecventa. Dezvoltarea de noi materiale dielectrice cu constanta dielectrica ridicata pentru aplicatii in domeniul microundelor si al undelor milimetrice. Aceste materiale au un potential de aplicatii foarte ridicat in domeniul comunicatiilor fara fir. Dezvoltarea de materiale feroelectrice de tip relaxor pentru aplicatii care necesita valori mari ale constnatei dielectrice si ale electrostrictiunii. Dezvoltarea de multistraturi dielectric-feroelectric, feroelectric-semiconductor, feroelectric-multiferoic, feroelectric-feromagnetic pentru a combina proprietati diferite in scopul obtinerii de noi functionalitati: efect de camp feroelectric, capacitate controlata prin numarul de interfete, cuplaj multiferoic la interfata, prezervarea proprietatilor feroelectrice/multiferoice reducand pierderile prin conductie, controlul proprietatilor prin controlul deformarii la interfete, etc. Dezvoltarea de modele teoretice care sa simuleze diferitele proprietati ale feroelectricilor sau multiferoicilor, cum ar fi comutatea polarizarii, formarea si evolutia domeniilor feroelectrice sau feromagnetice, etc. Avand in vedere evolutia ultimilor ani, atat in tara cat si pe plan international, cat si perspectivele viitoare in domeniu la nivel mondial consideram ca tematicile de interes pentru perioada 2011-2020 sunt: Dezvoltarea de noi materiale, de preferinta fara elemente periculoase pentru sanatate sau pentru mediu, cu proprietati dielectrice, feroelectrice, piezoelectrice si multiferoice imbunatatite. Aceasta presupune atat dezvoltarea de noi materiale masive cat, mai ales, dezvoltarea de straturi subtiri, multistraturi si nanocompozite cu proprietati imbunatatite si cu noi functionalitati. Tendinta este dictata in primul tand de necesitatea integrarii materialelor multifunctionale cu tehnologia semiconductoare, ceea ce presupune reducerea dimensiunilor (deci utilizarea de straturi subtiri sau nanostructuri), cat si de necesitatea utilizarii responsabile a resurselor existente, ceea ce inseamna utilizarea pe scara mai larga a compozitelor. Dezvoltarea de noi componente si dispozitive bazate pe materiale dielectrice, feroelectrice, multiferoice si piezoelectrice. Exista doua directii principale: a) utilizand materiale ceramice, ceea ce inseamna controlul precis al dimensiunilor grauntilor cristalini si al compozitiei chimice (in scopul reducerii fazelor parazite, si in scopul ajustarii proprietatilor macroscopice in functie de raportul volum/interfete in ceramica); b) utilizand materiale de tip monocristal sau straturi epitaxiale, ceea ce inseamna control asupra calitatii cristaline si dopajului, similar cu ceea ce se face in momentul de fata cu materialele semiconductoare. In ambele cazuri un rol din ce in ce mai important il vor juca interfetele. Va deveni deci foarte importanta intelegerea fenomenelor complexe care au lor la interfete in materiale dielectrice, feroelectrice si multiferoice. Investigarea fenomenelor fundamentale prezente in materiale dielectrice, feroelectrice si multiferoice, cu accent pe efectele de dimensiune si cuplajul intre diferite faze cu proprietati diferite. Exista o serie de probleme inca ne-elucidate la care cercetarea Romaneasca in domeniu si-ar putea aduce contributia: efectul magnetoelectric in multiferoici artificiali; transportul de sarcina de-a lungul interfetelor si perpendicular pe interfete; efectul deformarii si al sarcinilor de la interfete asupra marimii si stabilitatii anumitor marimi fizice; dopajul in feroelectrici si multiferoici; legatura in structura electronica si sarcina de polarizare; noi forme de inducere a ordinii polare, etc. Mai concis: Multiferoici artificiali Nanostructuri dielectrice, feroelectrice, multiferoice si piezoelectrice Multistraturi si super-retele Dopaj in materiale feroelectrice si multiferoice Efecte de interfata Cuplajul intre proprietati electronice si polarizare Tunabilitatea proprietatilor macroscopice Efectul radiatiilor asupra materialelor si structurilor dielectrice, feroelectrice si multiferoice
Referinte (2000-2011)
Grupuri principale	Institutul National de Cercetare-Dezvoltare pentru Fizica Materialelor. Universitatea Alexandru Ioan Cuza din Iasi Universitatea Bucuresti Institutul de Chimie Macromoleculara Petru Poni din Iasi Universitatea “Politehnica” din Bucuresti Institutul National de Fizica Laserilor, Plasmei si Radiatiei din Bucuresti
Infrastructura existenta	Exista o dotare exceptionala in laboratoarele romanesti in acest domeniu Institutul National de Cercetare-Dezvoltare pentru Fizica Materialelor. -instalatie de depunere PLD; instalatie de depunere prin RF-sputtering; facilitate de preparare chimica; spark plasma sintering, hot-pressing; facilitate de tratament termic si in camp de microunde -caracterizare structurala si compozitionala prin XRD, SEM, TEM si HR-TEM (incluzand EDX si EELS), XPS, XAS, PEEM-LEEM, ARPES, ARUPS, STM, diverse tehnici SPM. -caracterizare proprietati: spectroscopie dielectrice de banda larga, spectroscopie de THz, lant de masura complex pentru investigarea proprietatilor electrice/feroelectrice si fotovoltaice (include 2 statii criogenice, una cu camp magnetic vertical cealalta cu camp magnetic orizontal, domeniul de temperatura de la LHe la 400 K, mai multe criostate cu diferite domenii de temperatura, punti LRC pe domenii de frecventa diferite, electrometre, 2 testere feroelectrice, monocromator, surse de lumina), PFM si alte tehnici pentru determinarea proprietatilor piezoelectrice, doua instalatii VSM, SQUID si PPMS pentru investigare proprietati magnetice, de transport si termice; elipsometrie, etc. De completat pentru UAIC, UB, Petru Poni , UPB!!!